[Koha] ids exist in both tables *borrowers* and *deletedborrowers*

From koha/about <System Information> Problems found Patrons The following ids exist in both tables *borrowers* and *deletedborrowers*: 57 Yes, there is a borrowernr 57 in the table deletedborrowers with surname "test". And there is also a borrowernr. 57 in the table borrowers (this one is a real user of the library) What should I do to get rid of the deleted borrower 57? Regards Heinrich